Are christians the closest people to Muslims?

The People of the Book are closest. There is no trinity, no son of a God. Even though Musa (Moses) was given the Covenant for Jews only, the Noah laws are for Christians, but they changed so much. Islam also has the Noah laws in the Qu'ran, but didn't make God into a human being. Thus, a religious Jew, if given the choice of death, Christianity or Islam, is required to choose Islam. See 1stCovenant.org for the righteous God-Fearers that were around before and after the common era & still around today that didn't make a religion out of the Noah Covenant to know what was around in the time before Christianity took the Seven laws into their book of Acts & ended up with Pauline Doctrine and not the Petrine or Arian view which were the majority even until the 5th c. See Codex Sinaiticus (5th c. earliest Christian Bible) and the variants of over 30,000 that aren't in the modern Christian books.